Ena-DATASET-INSTITUTE OF CANCER RESEARCH-14-08-2017-09:54:45:886-145 - samples
Ontology highlight
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PROVIDER: EGAD00001003563 | EGA |
REPOSITORIES: EGA
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Project description:Diffuse intrinsic pontine glioma (DIPG) is a fatal malignancy of the childhood pons characterized by a unique lysine-to-methionine substitution in histone-3 at lysine 27 (H3K27M). We show here that the specific Polycomb targets disrupted by H3K27M and resultant oncogenic state is dependent on both the variant of histone-3 and the cell- context in which the mutation occurs. Through primary DIPG tumor characterization and isogenic expression, we show that the same H3K27M mutation displays distinct modes of oncogenic reprogramming and establishes distinct enhancer architecture depending on whether it occurs in genes encoding H3.3 or H3.1. By comparison to non-malignant pediatric pontine tissue, we create a molecular map for DIPG, identifying and functionally validating both shared and subgroup-specific pathophysiology. Directly comparing the earliest events of H3K27M tumor initiation in putative cells-of-origin demonstrates that DIPG arises only from an oligodendrocyte precursor cell state.
2019-10-03 | GSE126319 | GEO
Project description:Vanishing white matter (VWM) is a leukodystrophy that primarily manifests in young children. In this disease, the brain white matter is differentially affected in a predictable pattern with telencephalic brain areas being more severely affected, while others remain allegedly completely spared. Using high-resolution mass spectrometry-based proteomics, we investigated the proteome patterns of the severely affected white matter in the frontal lobe and normal appearing pons in VWM and control cases to identify molecular bases underlying regional vulnerability. By comparing VWM patients to controls, we identified disease-specific proteome patterns. We showed substantial pathogenic changes in both the frontal white matter and pons at the protein level. Side-by-side comparison of brain region-specific proteome patterns further revealed regional differences. We found that different cell types are affected in the VWM frontal white matter than in the pons. Gene ontology and pathway analyses identified involvement of region distinct biological processes, of which pathways implicated in cellular respiratory metabolism were overarching features. In the VWM frontal white matter, proteome changes were associated with decrease in glycolysis/gluconeogenesis and metabolism of various amino acids. By contrast, in the VWM pons white matter, we found a decrease in oxidative phosphorylation. Taken together, our data show that brain regions are affected in parallel in VWM, but to different degrees. We found region-specific involvement of different cell types and discovered that cellular respiratory metabolism is differently affected across white matter regions in VWM. These region-specific changes help explain regional vulnerability to pathology in VWM.
2023-06-28 | PXD040861 | Pride
Project description:We studied the effect of BMI1 inhibition in diffuse intrinsic pontine glioma cells (DIPG). We reported the application of chromatin immunoprecipitation sequencing for high-thoughput profiling of BMI1 and H2AK119ub in diffuse intrinsic pontine glioma cells (DIPG) in response to BMI1 inhibition. We also performed bulk RNA sequencing of DIPG cells in response to pharmacological inhibition or knockdown of BMI1.
2020-10-22 | GSE140768 | GEO
Project description:Human diffuse intrinsic pontine gliomas (DIPG) are an aggressive form of pediatric brain tumors that arise in the pons in young children thus resulting in significant morbidity and very poor survival. Recent data suggest that mutations in the histone H3.3 variant are often found in these tumors, though the mechanism of their contribution to oncogenesis remains to be elucidated. Here we report that the combination of constitutive PDGFRA activation and p53 suppression as well as expression of the K27M mutant form of the histone H3.3 variant leads to neoplastic transformation of hPSC-derived neural precursors. Our study demonstrates that human ES cells represent an excellent platform for the modeling of human tumors in vitro and in vivo, which could potentially lead to the elucidation of the molecular mechanisms underlying neoplastic transformation and the identification of novel therapeutic targets. Human ES cells were differentiated to NPCs and lentivirally transduced with a combination of constitutively active PDGFRA (D842V), sh-p53, and WT or K27M mutant form of histone H3.3 variant.
2014-11-21 | E-GEOD-55541 | biostudies-arrayexpress
Project description:Diffuse intrinsic pontine glioma (DIPG) is an incurable brain tumor that arises in the pons of children. Recent studies strongly suggest that roughly 30% of DIPG tumors contain copy number increases in platelet derived growth factor receptor A (PDGFRA). We established a novel mouse model by knocking in the human PDGFRA conditional to Cre exposure by crossing in germline Olig2-Cre (specific to oligodendrocytes). This knock in is used in conjuction with p53 tumor suppressor knockout conditional to cre exposure as well. Mutants contain the PDGFRA KI allele, while wild-types only contain p53 floxed alleles with Olig2-Cre. At 18 days of age, mutants demonstrate tremors and hind limb paralysis, and die shortly thereafter. The goal is to determine the differences in brain stems near the time of death in the presence of the PDGFRA mutation when compared to controls without this mutation.
2021-08-12 | GSE181899 | GEO
Project description:Purpose: More than 90% of children with diffuse intrinsic pontine glioma (DIPG) die within 2 years of diagnosis. There is a dire need to identify therapeutic targets, however lack of patient material for research has limited progress. We evaluated a large cohort of diffuse intrinsic pontine gliomas (DIPGs) to identify recurrent genomic abnormalities and gene expression signatures underlying DIPG. Patients and Methods: We used single nucleotide polymorphism arrays to evaluate genomic copy number imbalances in 43 DIPGs from 40 patients and in 8 low-grade exophytic brainstem gliomas. Gene expression arrays were used to evaluate expression signatures from 27 DIPGs, 6 low-grade exophytic brainstem gliomas and 66 low-grade gliomas arising outside the brainstem. Results: Frequencies of specific large-scale and focal imbalances varied significantly between DIPGs and pediatric glioblastomas outside the brainstem. Focal amplifications of genes within the receptor tyrosine kinase-Ras-PI3-kinase signaling pathway were found in 47% of DIPG, with PDGFRA and MET showing the highest frequency. 30% of DIPG contained focal amplifications of cell-cycle regulatory genes controlling RB phosphorylation, and 21% had concurrent amplification of genes from both pathways. Some tumors showed heterogeneity in amplification patterns. DIPGs showed distinct gene expression signatures relating to developmental processes compared to pediatric glioblastomas arising outside the brainstem, while expression signatures of low-grade exophytic brainstem gliomas were similar to low-grade gliomas outside the brainstem. Copy number analaysis: 43 DIPG samples, 8 Low Grade Gliomas using SNP6.0. Available matched normals are also profiled with SNP6.0. Expression analysis: 29 DIPG samples, 6 Low grade samples Please contact Suzanne Baker at Suzanne.Baker@stjude.org for CEL files and genotype calls.
2011-09-20 | E-GEOD-26576 | biostudies-arrayexpress
Project description:Diffuse Intrinsic Pontine Glioma (DIPG) is a rare and highly aggressive pediatric tumor. The average survival time after diagnosis is less than one year. Currently, there are no effective treatments. Characteristic of DIPG is a mutation in histone H3 which leads to a substitution of Lysine 27 to Methionine (H3K27M) which deregulates Polycomb Repressive Complex 2 (PRC2), including enzymatic activity of EZH2. Previous studies have shown that inhibition of EZH2 by chemical agents decreases DIPG cell proliferation and inhibits tumor growth in vivo. My thesis project aims to confirm that EZH2 could be a therapeutic target using chemical EZH2 inhibitors, small interfering RNAs and a CRISPR/Cas9 approach in a series of DIPG tumor cell lines and to determine underlying molecular mechanisms of action.
2022-04-01 | PXD017525 | Pride
Project description:During brain development, layer 5 neurons distributed across most areas of the neocortex innervate the pontine nuclei (basilar pons) by the initiation and extension of collateral branches interstitially along their corticospinally extending axons. We used microarrays to compare gene expression profiles of pontine nucleus when axon collaterals towards the pontine nucleus start to extend (embryonic day 17.5 (E17.5) to postnatal day 1 (P1)), and/or throughout the development (E17.5-P14) in order to understand genetic programs that regulate axon collaterals formation.
2020-11-30 | GSE140760 | GEO
Project description:Diffuse intrinsic pontine glioma (DIPG) is a highly aggressive brain tumour that is located in the pons and primarily affects children. Whole-exome sequencing studies have identified recurrent driver mutations in H3F3A and HIST1H3B, leading to the expression of histone H3 in which lysine 27 is substituted with methionine (H3K27M) in nearly 80% of DIPGs. H3K27M inhibits Polycomb Repressive Complex 2 (PRC2) activity by binding to its catalytic subunit EZH2 and although DIPGs with H3K27M mutation show global loss of H3 with trimethylated lysine 27 (H3K27me3), several genomic loci are still H3K27me3 positive. Here, we describe a new mouse DIPG model in which H3K27M potentiates tumourigenesis. Using this model and primary patient-derived DIPG cell lines, we show that H3K27M expressing tumours require PRC2 for proliferation. Furthermore, we demonstrate that small molecule EZH2 inhibitors abolish in vitro and in vivo tumour cell growth through a mechanism involving induction of the tumour suppressor protein p16INK4A. In agreement with this, we show that tumour cells with inactivated p16INK4A function do not respond to EZH2 inhibitors. By analysing genome-wide H3K27me3 enrichment profile in mouse DIPG model, we highlight distinct features of the loci that lose or retain H3K27me3 in H3K27M expressing cells. Taken together these results show that residual PRC2 activity is required for the proliferation of H3K27M positive DIPGs, and we propose a therapeutic strategy for these tumours using EZH2 inhibitors and expression of p16INK4A as a marker for stratifying potential responding tumours.
2017-08-31 | GSE71387 | GEO
Project description:Human diffuse intrinsic pontine gliomas (DIPG) are an aggressive form of pediatric brain tumors that arise in the pons in young children thus resulting in significant morbidity and very poor survival. Recent data suggest that mutations in the histone H3.3 variant are often found in these tumors, though the mechanism of their contribution to oncogenesis remains to be elucidated. Here we report that the combination of constitutive PDGFRA activation and p53 suppression as well as expression of the K27M mutant form of the histone H3.3 variant leads to neoplastic transformation of hPSC-derived neural precursors. Our study demonstrates that human ES cells represent an excellent platform for the modeling of human tumors in vitro and in vivo, which could potentially lead to the elucidation of the molecular mechanisms underlying neoplastic transformation and the identification of novel therapeutic targets.
2014-11-21 | GSE55541 | GEO